I know this is an odd one, but while attempting to get into creating texture packs/resource packs, I decided I wanted to make a pack for 1.2.6 to practice a bit and just get used to modifying textures. However, I ran into an issue, and cannot find anything on the internet that is useful for this. How do you change the textures of Lava/Water in Alpha 1.2.6? I've modified the terrain.png to include the custom textures, but when loading in game, they aren't present. Any suggestions?

I apologize if there's a better section to post this in, but I wasn't able to find a better one.

I know this is an odd one, but while attempting to get into creating texture packs/resource packs, I decided I wanted to make a pack for 1.2.6 to practice a bit and just get used to modifying textures. However, I ran into an issue, and cannot find anything on the internet that is useful for this. How do you change the textures of Lava/Water in Alpha 1.2.6? I've modified the terrain.png to include the custom textures, but when loading in game, they aren't present. Any suggestions?

I apologize if there's a better section to post this in, but I wasn't able to find a better one.

I've been seeing a lot of posts for old versions recently. I'm starting to wonder why.

But as to the topic at hand, sadly the answer to your question is "write a mod that does this".

Waaaaay back in the day Notch wasn't a very good programmer, or at least not a particularly feature-forward-thinking one, and so to do the liquid animations he decided to write the files into the code rather than into images. The result is that Minecraft is hard-coded to overlay its own animations onto the particular x and y coordinates on the terrain.png; effectively erasing whatever you put there.

MCPatcher initially existed specifically to solve this issue along with the related problem of the water, lava, and fire animations appearing overlaid onto blocks in the world incorrectly when higher-resolution textures were used. I'm reasonably certain that MCPatcher wasn't around in Alpha, and even if it was it doesn't work well with the modern launcher anyway. You can look into it further, but all I can do is wish you luck on getting it to work.

Barring that, it's pretty much back to my initial suggestion of writing your own mod that accomplishes this. Sorry to be the bearer of bad news.

You can check the Downloads page for Mcepatcher. The earliest one still listed roughly corresponds to the release of Minecraft version 1.4.7, though I have no way of checking right now if that's the version it's for. There were older versions at one time (I know MCPatcher was around in Beta), but I'm betting that they were removed for legal reasons after the whole Bukkit take-down; leaving only the versions that use MCPatcher's more advanced patching method that contains no original Minecraft code.

The complication is that none of those old versions work with the current launcher. You'll need to figure out how to manually edit some .json files for the current launcher to acknowledge an older patched version; as well as moving around a lot of files since at the time Minecraft had a very different folder structure. Even downgrading to the older launcher won't help much as Mojang retrofit all of the old versions to work with the new system. MCpatcher never made those retroactive changes, though, so the two are essentially incompatible.